Don't know about aptitude tests for CPL (flight test?). There is an aptitude test you can do with GAPAN (The Guild of Air Pilots and Air Navigators) at the RAF Cranwell testing facility for about £150.
If this is not what you are refering to please post back and state where and how you heard of aptitude testing for the CPL part of the training.
Hope this is of some help,
BM.